Guido semenza



G. SEMENZA.

ELECTRC INSULATOR.

APPLIC'ATIQN man 1AN.23.1918.

Patented Mar. 16, 1920.

UNITED STATES PATENT OFFICE.

GUIDO SEMENZA, OF MILAN, ITALY.Y

ELECTRIC INSULATOR.

' To aZZ ywhom t may concern.'

Be it known that I, GUIDO SEMENZA, subject of the King of Italy,resident at Milan, in the Kingdom of Italy, No. 10 Via Santa Ravegonda,have invented new and useful Improvements in Electric Insulators, ofwhich the following is a specification.

, This invention relates to insulators of the suspension type in whichthe insulating member of porcelain, glass or any other insulatingmaterial, carries on its upper part a metal cap, fixed to itin someappropriate way more generally by means of cement.

he principal object of the invention is to provide a new and improvedconstruction,

y combination and arrangement of parts by which any stresses due todifferent rates of expansion or contraction of the materials used may beavoided or so directed that they will not cause the breakage of theinsulating member.

In effecting this object, the arrangement adopted and hereinafterdescribed is of such a character as not to require any -cement or othermatter to be employed in order to fix the cap to the insulating element,and a space is provided to allow expansion and contractions of thedifferent parts employed without generating dangerous stresses. A

The invention has also the object of rendering difficult the falling outof the insulating member from the cap when for any reason it fails owingto mechanical actions or an electric flash over, or when it becomespunctured. f

In the accompanying drawings, Figure l is a view partly in section andpartly in elevation of an insulator having a conical shaped head,carried by a metal cap, made to properly fit it, Fig. 2 is a sectionalview taken on the line A B. The construction and shape of the cap may bevaried as required: in the figures one example is given to show theprinciple of the invention.

Inthe figures; 1 is an insulator of the Y suspension type the particularform of which has no importance provided that the head be made in theform of an inverted cone; care should be taken that the portion 7 8 ofthe surface of the insulator should be as nearly as possible accuratelyconical.

The cap is made of three parts: a round top piece or disk 9 and twosemi-annular side pieces 5. The three parts of the cap may be of anykind of suitable metal vsuch as cast-iron or steel, and the top piece orpart Specification of Letters Patent. Patented *M313 16, 1920..Application filed January 23, 1918. Serial No. 213,316. i i

is spaced from the top of the insulator, so as to permit expansion totake place to different extents.

It will be noted that the two side pieces 5 form in the interior aconical surface which must have the same inclination as the conicalouter surface 7 8 of the insulator 1.

In order to obtain a continuous contact between the cap and theinsulator the inner conical surface of the cap is faced with a layer 6of very soft metal which can be, if necessary, turned out or adjusted byany other suitable means.

This soft metal may be cast on the two side pieces 5 in which twodovetail grooves (12) as shown in section in Fig. 1 are formed. It mayalso be pressed in place by any known mechanical process.

In the place of this coating of soft metal a layer of any other suitablesoft substance can be used.

The three parts of the cap are kept together by bolts 11.

10 is a threaded hole for fastening the upper eyebolt. The inner rod 4:may be fixed to the insulator by means of cement or by a layer ofelectrolytically deposited material in which the rod is screwed, or byany other appropriate means.

It can be easily understood that the insulator when suspended will forceits conical surface against the soft metal or other interposed materialand will tend to contact squarely with it all over.

As a result of this fact it will be seen that all mechanical strain willbe distributed over a large surface, and the resulting stresses imposedupon the porcelain will be only comv pression.

Owing to the conical shape of the surfaces in contact the insulator isfree to move up and down in the cap, and the differences of expansionbetween the porcelain and the metal cannot produce any overstrain butwill result in a slight relative motion. A As to the danger of theinsulator falling out of the cap when the insulator breaks for anyreason, it will be seen that, owing to the conical shape of the head theliability of this happening is very much reduced.

Having now described my invention and how the same is to be carried out,what I claim as my invention, is:

1. A suspension insulator, comprising an insulating element having anouter conical surface; and a suspension cap consisting of a top memberinthe ormof a dislgand a pair of companion, semi-conical side memberscccllccccd cc Said ccp* member; andina- Yigg their inner surfacesuniting to provide a singie, continuous conical surfaceAwhichicon-Vformably fits against and movably rests upon fthe srSt-nemcd fccniccl-Surface -fchcccehccc its entire extent, both conical eurfacesyhaw ing'their apices directed downward; said tog member Yhanging Yitswlow'ersurface Nspace mentwhenbaid conical surfaces trein-uch cceeecmcct, tcprcrclc. @clearance ,space .wh1'challcWS i'crchc cxpjenclcnicf Said, ccp

ten

v2- A c ccpcyccn,.inculatcr, c01.1219rising en ,clemence clement cfrlcrcccc matcmlhav- 'i ineen cctcc -ccncel cuiifwcc a.. aWmetelucwrceclcn cclcccncl lthc'ierm efellfllsl Nside members connectedto said top member and having thelr inner surfaces uniting to `yprovideia,single continuous conical surface which has the same inclination `asthe first- .namedconical surface, both conical surfaces 4Whaving theirvertices directed downward;

ineulatinglelement when said conical sur-` jniaeexsnaregin .suchengagement, to pro-Vide, a

clearancerepace which allowsor the Aexpanvsion of .caido/ap vandsa'idinsulating element .cci ,clrent cXtencS- Y f ""lnrtestimony whereof Iaffix-V my sig1 1ature.l

1 GUID@ cenit-rnc,ZAv

